Control for toric friction transmission



3 SheOts-Sheec 1 www J. O. ALMEN ET AL CONTROL FOR Tomo FRIOTION TRANSMISSION Filed Dec. 20, 1954 June 23, 1936.

l# N .WTR e www Nw u June 23, 1936. I J. o. ALMEN T A| 2,045,558

CONTROL FOR TORIC FRICTION TRANSMISSION Filed Dec. 20, 1954 3 Sheets-Sheet 2 June 23, 1936. Jfo. ALMEN ETAL 2,045,558

CONTROL FOR TORIC FRICTION TRANSMISSION Filed Dec. 20, 1954 3 Sheets-Sheet 3 gmc/who@ Patented June 23,l 1936 STATES John 0.v Almen, Royal Oak, and Winileld D. Gove, Detroit, Mich., assignors to General Motors Corporion, Detroit, Mich., a corporation oi? Delaware Application December 20,1934, Serial No. 758,394

25 Claims.

This invention relates to mechanism for controlling ratio changes in friction raceand roller transmission mechanisms. It is particularly applicable to transmission mechanism of race and roller type in which the direction of rotation of the races and rollers is reversed when the output shaft or other output element is being driven in reverse.. y

Major objects of the invention are toI enable the .ratio position oi all of the rollers to be changed simultaneously and equally and all restrained to track in similar paths on the races, whether the races and rollers are being rotated in the direction of forward driving or in reverse; to initiate ratio changes during both forward and reverse driving, by inclining the rollers about axes connecting the roller centers with the points oi contact of the rollers with the races and automatically restoring the. rollers to the normal stabilized position by means of two selectively actuated linkages operative respectively during forward and reverse driving.

The invention consists in ratio control means for a friction transmission mechanism of the type specied comprising races and interposed rollers adjustable to different ratio positions. and rotatable in one sense during forward driving and in the opposite sense durlng'reverse driving, said control means including one set of actuating devices for adjusting the ratio position of the rollers during forward driving and another set for adjusting the ratio position of the rollers during reverse driving, and means for rendering one set or the other operative according to the direction of rotation of the races and rollers. It further consists in universally pivoted carriers for the rollers, and control means including one set of links connected to the carriers on one side of the roller axes and another set of links connected to the carriers on the opposite side of the roller axes and means for selectively actuating one set of links for adjusting'the ratio 'during forward driving and the other set of links for adjusting the ratio during reverse driving. It further consists in means responding to the direction of rotation of the driving races for selecting and rendering operative that set of ratio position vadjusting devices that is appropriate to the direction of rotation of the output member and simultaneously freeing the other set. It further consists in various combinations and sub-combinations for accomplishing the objects of the invention'y lto be disclosed fully in the detailed description following. v

(Cl. F14- 200) In the drawings, in which like parts are indicated by like reference characters throughout the several views,

Fig. .1 is a section through the casing of. a motorvehicle transmission mechanism embodying this invention and exposing the mechanism within the casing partly in vertical longitudinal section;

Fig. 2 is a transverse section on a plane indicated by llne 2-2 of Fig. 1;

Fig. 3 is an elevation of an automatically adv l0 justable coupling and control ring viewed in the direction of the axis of the output shaft from the rear;

Fig. 4 is an elevation of a fragment of an automatically reversible control tube, which positions L the coupling and control rings, one of which is shown in dotted lines surrounding said sleeve;

Fig. 5 -is a development of the inner surface of the coupling and controlv ring.

Fig. 6 is an elevation of a fragment of the transmission casing broken away to expose the mechanism within shown partly in section.

Fig. 7 is a section on line l--l of Fig. l;

Fig. 8 is a detail of one end of a reversible expanding clutch spring for temporarily clutching the control sleeve to the driving races.

The invention is illustrated in a duplex friction race and roller transmission mechanism designed to be disposed behind the rear axle of a motor vehicle and operated from an engine mounted in front of said axle through a power input shaft geared to the driving races and offset from the power output shaft; the latter is coaxial with the races and drives the rear axle shaft from its forward end. The invention however is not limited to the particular mechanism with which it is shown. l

In the drawings I0 indicates a transmission casing for housing a duplex friction power transmission mechanism lncludlng two sets of races withv opposed toroidal raceways and interposed rollers for transmitting rotation from one race of each set to the other race of the same set.

Fixed within the casing I0 is an inner support-l ing and strengthening frame'comprising separated, parallel transverse members l2, i2, rigidly united by a partially cylindrical web4 le. Flanged coaxial tubular bearing elements I6 and I6a snugly t alined holes in the members l2 ,L and l2, and are rigidly united thereto, as by bolts it, it, passed through the flanges into said members. The inner ends of tubular bearing elements i6, i6 are spaced apart axially to admit an expansible friction clutch device to be hereafter described, and are equipped respectively with ground trips? I'I, Il'A cooperating with the clutch device.

Each of the members I2 and I2 has a plurality of openings I2 arranged around the center for admitting the transmission rollers interposed between the races previously referred to. The rollers are mounted infcarriers movably attached to the supporting members I2 and I2'L as hereinafter explained.

Input shaft section 20, designed to transmit the power of an engine, not shown, to the transmission mechanism enters the front end of casing I0. It is assumed to rotate clockwise viewed from the left of Figs. l and 6. The rear end of shaft section 20 is reduced and piloted in the front end of a continuation input shaft section 20 (Fig. 6) rotatable in bearings in supporting members i2 and EZB and carrying a driving gear 2t fixed thereto between the bearings. Fixed to shaft section 20a is a hollow cylindrical clutch member 24 which extends over the rear vend of shaft section 20, and is provided with internal clutch teeth 20. A reverse driving gear 28, having an integral hub like sleeve equipped with external clutch teeth 32 adapted to interlock with the internal clutch teeth 26 of member 24, is

- at 06, Fig. 1.

slidably keyed to shaft section 20.

The output shaft is indicated by numeral 40. The front end of shaft 40 is supported in a bearing 42 seated in front wall 44 of casing I0. Forward of bearing 42 shaft 40 carries a bevel pinion 46 designed to mesh with the ring gear of a rear axle differential (not shown). A reverse gear 48 is fixed to rotate with output shaft 40 and is adapted to mesh with gear 28 slidable on input shaft section 20. Shaft 40 extends through tubular bearing elements I6, |6P- and through a control tube, to be presently described, capable of limited rotary movement, disposed between the shaft and said tubular bearing elements and having bearing engagement at its ends with the shaft.

During forward driving, power is transmitted from the input shaft sections 20-20* through gear 22 to power output shaft 40, through the two halves of the duplex transmission mechanism by means now to be described.

Front and rear races 52 and 52B, having toroidal raceways, are connected to shaft 40 so that shaft and races are compelled to rotate together.

Gear 22 on input shaft section 20 meshes with a gear 60 secured to a tubular hub-like member 82, having a slightly enlarged central bore and portions projecting axially fore and aft of the gear, the inner peripheries of the projecting portions having bearing contact with the outer end surfaces of tubular bearing elements IS, I6 and the outer peripheries of said projecting portions serving as bearings on which the toroidal driving races 64, 04*I are mounted. Races 64 and 64I*l are vpreferably rotated by and with gear 60 through balanced or differential devices such as rollers seated in slots in said gear and rotatable about radial axes, one of said devices being indicated The races 64, |54a and gear 60 may, however, be maintained in power transmitting engagement by any suitable means.

Power transmitting rollersare interposed between the driving and driven races of each half of the transmission. There are preferably a set of .three rollers 10 between driving race 64 and driven race 52 and a set of three rollers 10a between driving race |i4a and driven race 52a. The carriers in which the rollers are mounted cannot revolve about the axis of the output shaft, but'are so anchored on the frame work of the transmission mechanism as to allow the rollers to incline about axes 'joining their points of con- -tact with the races and to tilt so as to change vtheir tracks on the races.

As is usual in race and roller transmissions of the type shown the races may be adjusted axially in such manner as to squeeze the rollers between them in order to produce that degree of traction which' is necessary to move the load. The required pressure is intended to be applied by spring and torque loading devices of any suitable construction, not shown in the drawings as they are disposed within the flange 50 and cover 56, which rotate with the race 52a, and constitute no part of this invention.

Suitable carriers for supporting and positioning rollers l0, 10e, respectively,v are indicated by numeral 80. Numeral is applied to the carriers in which rollers lila as well as rollers l0 of the forked carrier depart, and which will here be designated the base of the carrier. Each supporting member I2 (o1` |2) as shown, is disposed between a driving and a driven race, and each carrier is moored to it so that the roller mounted in said carrier may rotate, incline, or tilt within one of the openings 12.

Ihe universal joint by which each carrier 80 is moored to the supporting member I2 (or |2) consists of an undercut spherical cavity 82 in the front, or that side of the base of the carrier 1 which is nearest the supporting member, articulated with a spherical head 84 on a mooring pin 86 secured to the adjacent face of said supporting member. The details of structure of the universal mooring are not material to this invention and have been fully disclosed in a prior patent application.

The parallel limbs of each carrier 80 have at their free extremities alined bearing openings |00 for the axle |04 fixed to a roller as illustrated in Figs. 1 and 6. Lateral gaps |02 in the limbs of less extent than the diameter of the openings |00 and communicating therewith permit the insertion, laterally, of the axles |04, since they are of a diameter not greater than the width of the gaps. Thereafter capped bearing bushings |00 of an external diameter to t tightly in the openings |00, may be inserted endwise into the openings and over the ends of the axles |04 and locked in place by keys |08. The inner ends 'I'hat surface of the carrier which faces the drlving race 64 (or 64e) is herein referred to as the carrier front. That side of the carrier which is adjacent a driven race is deemed to be the back. Each carrier may swing in any direction about the center of the ball headed mooring pm The tangential driving force of a driving race 64 or il* on a roller 'I0 or 10, and the tangential reaction force between a roller 10. or 1|!n and a driven race 52 or 52", during forward driving, are exerted in a direction from the anchoring pin through the roller center so as to cause said carrier 80 to trail, as will be apparent on inspection, keeping in mind that input shaft section 20a during forward driving rotates clockwise viewed from the left of Fig. 6, and therefore driving races B4, 64 rotate counterclockwise, as so viewed.

In the transmission' mechanism illustrated, rearward or reverse driving is eiected by disconnecting clutch jaws 26 and 32 and by meshing reverse gears 28 and 4t, thereby shunting out, or by-passing, the race and roller mechanism, and driving output shaft t by a gear connection from input shaft 2G. During reverse driv-` ing obviously the races 52 and 52e, which rotate clockwise during forward driving (as viewedvfrom the left of Fig. l) when they transmit the power of the engine to the output shaft tt, are now rotating counterclockwise and are not delivering any torque except what is necessary to rotate rollers MRM, races td, 5d, gears t@ and 22 now rotating without transmitting torque.

During reverse driving, although there is no substantial load resisting rotation of rollers, races and'gears t@ and 22, yet such tangential forces as are exerted by theI races upon the rollers are also in a direction to cause the carriers t@ to trail as described with respect to forward driving.

The mechanism thus far described is not claimed herein. The invention ofthis application is involved in the means for controlling the ratio position of the rollers both in forward and reverse driving. This control means will now be described. l

In Figs. l and 2 numeral |||l indicates a control shait disposed radially outward of the friction rollers'and races and parallel with the axis of shaft dii, which is the main axis of the transmission. Shaft ii@ is supported in a bearing bracket |2 attached to member l2 and in a bearing bracket H2 attached to member |23. The

ends of the control shaft extend through the bearings. 4'lo the forward end is secured an arm IM and to the rearward end a bell crank iid having an arm Hd, corresponding to arm iid on the forward end. and also an arm it. A master control link H8 is pivoted to forward arm Ht and a similar link H8 is pivoted to rearward arm Hd. Master links iis transmit motion from control shaft when it is rocked, to trains of intermediate mechanism between said links and the rollers in order to effect a change in ratio position of the rollers. Rocking movement may be imparted to the control shaft by direct connection to a governor, handle, pedal or the like, or by an indirect connection through. a servomechanism. In the drawings arm H6 is shown connected to the output element |22 of a servomechanism l2@ of any suitable construction. For the purposes of this invention it isI suiiicient to say that in response to manual or governor eiort the servo-'mechanism imparts axial movement to the servo output element |22, which moves arm l It, thus rocking the shaft ||0 and the arms Htl, secured to the opposite ends, in one sense or the other according to` Whether` a shift to high or low ratio is contemplated.

Reference has previously been made to a control tube surrounding output shaft C0 .and disposed inside of tubular bearing elements I6 and ISB. This control tube is indicated by numeral |30. Split retaining rings |3| seated in grooves in tube |30 next to the flanged ends of bearing elements I6 and I6n assist in positioning the tube longitudinally. The ends of tube |30 are lined with bearing bushings |32 in bearing contact with shaft 40, which is slightly reduced in diameter between said bushings to admit oil. Holes |34 in tube |30 and tubular bearing elements i6, I6 admit oil from annular grooves in the memhers |2 and |28, the oil being supplied by pressure lubricating mechanism not shown.

Sleeved over each end of control tube |30 is a pair of juxtaposedratio control collars |36 and |36, These collars are cup like, and have substantially cylindrical internal surfaces merging into conical surfaces idd. Their rims are in substantial contact and both may rotate on the control tube |30 with which their bearing flanges M2 are in loose contact,-hence, capable of limited transverse movement. Atthe iianged ond each collar |36 and 536- is provided with three radiating lugs lit and itil, respectively, 2.

for the attachment of links, the other ends ci which are attached to the roller carriers byV means to be described presently. Collars |56 and |36El are provided with corresponding opposed rectangular notches Mii and It having flaring entrances. Each-collar has two. of said notches diametrically opposed. Notches M6 and Etta are shown at the left end of Fig. 1- on the near side in full lines and at the right of Fig. 1 on the farfside in dotted lines. Said notches function as clutch dogs to engage diametricaliy opposite coacting dogs Ult, |48a on. an automatically controlled coupling ring ld. and |369' are held in place axially by snap rings |52.

Links |56 connect collar |36 with carriers ad. Links |5t are universally jointed to lugs idf of collar |36 at one end and at the other end to arms |58 projecting from the backs of the carriers. Collars |36 and links |5t control the ratio positions of the rollers lll (or ma) during forward driving.

Links it universally pivoted to lugs Wie on collar |36 at one end and vto arms ISB projecting from the fronts of the carriers control the ratio positions of the rollers 'it (li) during reverse driving. i

The master control links H8, respectively pivoted at one end to the arms |-|l| on the ends of said shaft, as previously mentioned, have their other ends respectively pivoted to the dogs Ulti on control coupling rings |50, as indicated by dotted lines in Fig. 1, at the right, each link H8 having a pin projecting at right angles therefrom into a hole M9 (Fig. 3) in dog |683. apparent that a rocking movement imparted to control shaft H@ will rock each control coupling ring |5ll, and the rockingV of control coupling rings |50 willcorresponoingly rock either ratio Collars i3@ S0 it is 60 control collars |36 Aor ratio control collars @153,65

depending upon whether the dogs |43, idd of control coupling ring |50 are interlccked with the notches |66 or |56E of control collars |36 or 3&1.' ,Control coupling rings |50 are automatically coupled with control collars |36 during forward 70 driving and with control collars |36 during reverse driving by means to be now described.

Control tube |30 is capable of turning apartial rotation about its axis in both senses ofV rotation. -Control couplings |523 have one or more internal grooves each groove consisting of helical portions |60 merging into circular portions |62. Bosses, preferably in the form of steel balls |64 seated in cavities in control tubes |30, engage the grooves in controlcoupling rings |50. 'I'he balls are so positioned with respect to the circular and yhelical portions `of the grooves that each ball is in the same relation to the circular and helical portion of its groove as every other ball. If, for example, one ball is midway of a circular portion, the other balls are also midway of a circular portion; or if one ball is at the beginning of a helical portion, all of the others are at the beginning of a helical portion. It will be apparent that when -a control coupling ring is positioned vso that circular portions of the grooves engage the balls, the coupling or the tube may be rotated a limited extent without imparting axial movementI to the coupling; but that when the helical portions of the grooves engage the balls rotation of the tube or coupling will cause the latter to moveaxially. When the balls |64 are midway of circular portions |62 of the grooveor grooves the coupling |50 should be in complete engagement with either collar |36 or |368. In Fig. 1 it is shown in full engagement with collar |36, the end of the coupling ring engaging the conical surface |40 and centering the collar. Under this condition a rocking movement imparted to control shaft ||0 will rock couplings |50 and collars |36 a partial turn and adjust the ratio position of rollers 10, 10H.

If control tube |30 be rotated a partial rotation while coupling rings |50 are in the positions shown in Fig. 1',no movement is imparted to the coupling rings until the tube has turned far enough to engage the helical portions of the grooves with the balls, whereupon further rotation of the tube |30 tends to impart axial movement to the coupling rings. 'I'he helical grooves in the rear coupling ring |50 are pitched right handed and the helical grooves of the forward coupling ring |50 are pitched left handed. Consequently, a rotation of tube |30 counter-clockwise (as viewed from the left of Fig. 1) will tend to force rear coupling ring |50 rearward to the position shown in Fig. 1 where its dogs interlock with rear collar |36; and to force forward coupling ring |50 forward into similar engagement with forward collar |36. If the control tube be rotated clockwise the coupling rings |50 will be caused to interlock similarly with the `collars |36, When couplings |50 are'interlocked with collars |36, rocking of control shaft ||0 adjusts plings |50 are interlocked with collars |36a rocking of said shaft I0 adjusts the ratio position of rollers 10, 10'I when the drive is in reverse. It is apparent that the reverse ratio control collars |36 are completely freed from any connection to the control shaft I0, and from any restraint with respect to rotation, when the forward'drive ratio control collars are locked to the coupling rings 50 and therefore compelled to respond to any rotation of the control shaft; and that when the reverse control collars |36a are locked to control coupling |50, the forward drive ratio control collars |36 are similarly freed.

Control tube |30 is automatically rotated in a counter-clockwise direction (as viewed from the left of Fig. 1) during forward driving until coupling rings |50 are forced axially into interlocking engagement with control collars |36, and in a clockwise direction during reverse driving until coupling rings |50 are forced intheopposite direction into interlocking engagement with control collars |361. 'I'he means for effecting the described automatic action will now be described.

As shown in Fig. 1,I a helical clutch spring |10 encircles the central zone of control tube |30, occupying the annular space between tube |30 and the peripheral Wall of the enlarged bore within hub-like member 62 which is limited in axial extent by the ends of tubular bearing elements |6, |68. Coiled clutch spring |10 is so tensioned, or biased, as to expand, unless forcibly contracted, into light frictional engagement with the inner surface of hub-like member .62. Each end of clutch spring |10 is furnished with a thickened end piece |12 (Figs. 1 and 8). Rigid with control tube |30, and juxtaposed to the ends of spring |10 are two spring Aabutments |14 and |14, The extremities of spring |10 are disposed normally in position to respectively thrust against the abutments |14 and |14. These abutments may be formed by notching or rabbetin-g at diagonally opposite corners a rectangular vblock of metal, secured to tube |30, as indicated in Fig. 1, so as to form the projecting abutments |14 and |14a each of a length substantially equal to the width of a spring end |12.

The ground trips |1, |1n on bearing elements I6, `|6a are disposed in position to engage the shoulders |18 on the respective thickened spring ends |12. The ground trips' are angularly displaced one from the other sufficient to permit rotation of tube |30'enough (about 270 in the construction shown) to completely disconnect coupling rings |50 from collars |36 and connect them with collars |36, or the reverse, as will presently appear. Clutch spring 10 therefore functions as a two way acting automatically releasible clutch. y'

In Fig. 1 the transmission mechanism is shown in neutral with the forward drive controls coupled to the control shaft |0.' It is to be exupected that the transmission will be in low when the gear 26 is shifted into neutral; but for simplicity of illustration the transmission is shown in the drawings in 1:1 ratio. If the slidable reverse gear 28 on the input shaft of a transmission in this condition be meshed with reverse gear 48 on the output shaft, and the engine clutch engaged, the following actions will take place simultaneously, to wit: The vehicle will start backward, shaft 40 and races 52, 52* will 'start to rotate counter clockwise (riewed from the left of Fig. 1), races 64 and 64, gear 60 and hub `member 62 will start to rotate clockwise and gear 22 with shaft section 20a will start to rotate counter clockwise,all parts of the transmission except shaft section 20 rotating reversely of the direction of rotation in forward driving. Since hub-like member 62 now starts to turn clockl within hub-like member 62 and begins to rotate with it; the right hand spring end pushing against abutment |14 rotates control tube |30 clockwise, thus withdrawing j control coupling rings |50 from engagement with collars |36, re-

leasing the ratio controls for forward driving,

centering and locking collars |36 to said' couplings |50, and so connecting the control mechanism for reverse driving to the control shaft ||0. Control tube |30 having rotated for enough to change the control connections as described,

the shoulderll on left hand end |12 (as viewed in Fig. 1) of clutch springk |10 engages ground trip Il and causes spring lli! to contract and release the frictional connection with hub-like.

member 62, which continues to rotate until the -vehicle is stopped or reverse gear disconnected.

If-'now the reverse gears be disconnected and clutch elements 32 and 26 be engaged and the transmission be started in forward drive, hublike member 62 turns counter clockwise, thereby v forcibly expanding spring clutch element il since the -lefthand end H2 (referring to Fig. 1)

pushes against abutment lle and rotates control tube i3d counter clockwise until the shoulder H8 on the right hand end of spring il@ engages ground trip lla, whereupon the spring is contracted and released from irictional engagement with hub-like member y522. Member 62 thereafter continues to rotate vwhile the control tube remains stationary. During rotation of the control tube counter clockwise control couplings i have been caused to move axially far enough to release control collars E36 and engage and center .control collars |36, thus connecting up the controls for forward driving.

Operation l Figs. l, 2, and 6 show the mechanism in neutral since clutch elements 32 and 2d as well as gears 28 and d8 are disengaged.

It is observed, however, that couplings idd are in engagement with ratio control collars ld as if the transmission had been placed in neutral during or immediately following forward movement of the vehicle. In Fig. l, therefore, the elements for effecting ratio control are related as they are 'during forward driving.

Ii" now, imagining the vehicle to be traveling forward, and in gear, control shaft lid be rocked clockwise, as viewed from the rear in Fig. 2, a

iid and masterviinks itil will rotate control cou--y plings i5@ and collars i3@ clockwise. Links le@ will therefore swing carriers @il about the center of the mooring joint until the bushings it@ in the outer limbs of the carriers contact with the outer faces of the rollers. In so moving it is obvious the axes of the rollers will be inclined slightly so as to pass to one side of the axis of the output shaft titl, whereas they intersect said axis of shaft di) during normal operating conditions. Since the driving races are now rotating clockwise (as viewed in Fig. 2 from the rear) the rollers will be steered outward in increasing .spirals on the driving races ed and @de and inoutward on the driving races and inward on they driven races each carrier tilts about a restoration axis inclined or oblique to the planes of the races determined by the fixed center of its mooring joint and the now fixedY point of connection of link i5@ to armi, which is oset from they back of the carrier as indicated most .clearly in Fig. 1. 'Tilting about this oblique restoration axis soon brings each roller axis to its normal position in which its extension intersectsythe main axis, that is, ythe axis of shaft. ed.

Obviously, if control shaft il@ be rocked coun-i' ter-clockwise (viewed as in Fig. 2) arms IM and master links I8 will rock couplings |50 and control collars |36 counter-clockwise, inclining carriers Bil so as to point the axes of the rollers to the other side of the axis of shaft lll-thus steer- 5 ing the rollers in a spiral diminishing on the driving race and increasing on the driven race, thus causing them to tilt toward a lower speed ratio position. Again each carrier 8@ will sg about a restoration axis inclined to the planes of the races determined by the center of the mooring point and the pivotal point of the con nection between link 556 and arm ld on the carrier. And itwill be perceived that as the roller and carrier tilt around this axis the l5 of the roller will be restored to a position whereV it points to the axis of shaft Se. When the axes of the rollers if extended intersect the axis of shaft dii the latter are in normal drivingpositions and track in circles on the races, as is obvious.

While driving forward, control coupling rings ld have been released completely from control collars i368 as is evident. The released collars are loose on the control tube i3d and free to rotate the limited extent made necessary by the 25 incllning and tilting movements of the rollers and their carriers, the latter being connected to the collars |368 by the links i563 as described.

The possible relative rotary movements of collars |36 and |36Es are small and never so great 30 as to misaline the clutch notches le@ and idd sumciently to prevent the dogs it@ and idem from gliding from the one notch to the other. The flaring sides of the notches will pilot the dogs MS, idee from one notch to the other even 35, though in so doing some motion may be imparted to the roller carriers. In the dran the notches are shown exactly alined. when the e e.; sion' ratio is lz. The mechanism may be desi ned to have the notches alined when in low spe@ ratio, or in any ratio.

` 'It now the gears Eil and te be meshed input shaft connected to the engine, output shaft d@ will be rotated in reverse and the vehicle driven rearward as previously explained. dirait till is nov.: rotating counter clc-c as vviewed from the left oi Fig. l., or clockwise as viese@l in Fig. 2 from the rear. Control tube i3d now' becomes clutched to hub-like member Si which is being rotated counter clockwise (from the point oi' view of Fig. 2) and shifm control coucling rings i5@ out of engagement with collars into engagement with collars iste, completely releasing the forward drive ratio control mechamism and coupling the reverse drive control mechanism to the control shaft iid. Now, rocking shaft il@ clockwise as viewed in Fig. 2, rotates coupling rings ld and collars i3d as T- wiselinlrs ist, connecting collars ilt to Seite on carriers ed, incline the carriers and roller axes in a direction to cause the rollers to spiral outward on races ttl, te, since they are now rotating counter clockwise, and to spiral inward on races 52, 52e, now being rotem clochwise'by the output shaft tid. ,The ends of links 65 lede connected tolarms litt are xed in space after adjusting movement of control shaft has cemed, and as the rollers tilt to new ratio sitions each carrier tilts about a restoration i deteed by the center of the mooring joint 70 and the connection of link |56 to lelie, therebycausing the roller-axis, which heeeV inclined ,to one side of the axis of st dil,-

to become restored tothe position wherein if extended it again intersects said am's. fle

fieA

So, also, if control shaft H0 be rocked counterclockwise, as viewedin Fig. 2, control -collars |ll|ia will turn counter-clockwise, and through` link connections |56a to arms |58A will incline the rollers and carriers so that the rollers will now spiral inward or races 64 and 64* and outward on races 52 and 52a. As the rollers and carriers tilt to a new ratio position each carrier will tilt as before around an axis determinedby the center of the mooring joint and the connecting point of link Iiiil to arm |58'. Thus the roller axes which are inclined to one side of the axis of shaft 40 become ,restored to the normal position wherein extension of the roller axes intersect the axis of shaft 40.

The restoration axes determined by the center of the mooring joint and the end of links |56 connected to the carrier when the transmission is in forward drive, and the restoration axis determined by the center of the mooring oint and the ends of links |56a connected to the carrier when in reverse are inclined oppositely with respect to the planes of the races, in order that proper restoration of inclined rollers to normal running positions may be eiected in whichever sense of rotation the racesmay be turning.

Control shaft I I0 is operated in reverse exactly the same as in forward driving. 'I'lie selection of forward or reverse controls by the control tube |30, which responds automatically to the sense of rotation of the transmission mechanism renders it unnecessary to make any change in the mode of operation of the control shaft whatever the direction of drive. By the double autofmatically selective linkages of this invention the rollers are always kept within bounds while operating in reverse as well as Whencperating in forward drive and all tendency for them to run off the races or assume unequal shares of the load are repressed.

We claim:

1. In friction transmission mechanism, the combination of a race capable of rotating in either sense of rotation, a roller, the periphery of said roller being in power transmitting engagement with the race and its axis lying normally in a radial" plane including the race axis and the roller center;v a roller carrier; two independently operative means respectively arranged to transmit force to the carrier for vmoving it to cause the roller axis to move out of said radial plane, an external control device, and means for operatively connecting the latter to one or the other of said independently operative means.

2. In friction transmission mechanism, the combination of a race capable of rotating in either sense of rotation; a roller, the periphery of said roller being in power transmitting engagement with the race and its axis lying normally ina radial plane including the race axis and the roller center; a roller carrier; two independently operative means respectively arranged to transmit force to the carrier on opposite sides of the roller axis in order to incline the roller about a straight line passing throughl its center and the point of contact of its periphery with the race, and external control means for actuating the independoperative means respectively connected to the carrier on opposite sides of the roller axis, to incline the roller about a straight line passing through its center and thepoint of contact of its periphery with the race.

4. In friction transmission mechanism the combination of reversible coaxial races and interposed rollers and means for supporting each roller with its axis normally in a radial plane including the race axis and the roller center but so that the roller axis may be displaced out of said plane and in consequence the roller tilts to change its path of contact with the races; two sets of control devices arranged to operate on the means for supporting the rollers, one for displacing the roller axes during forward rotation and the other for displacing the roller axes during reverse rotation, and means responding to reversals of rov tation of the transmission mechanism for rendering one set of control devices operative and the other inoperative according to the sense of rotation of the races and rollers.

5. In friction transmission mechanism having reversible coaxial toroidal races and interposed rollers, a frame, a. roller carrier for each roller universally pivoted to the frame, and means for controlling the ratio position of the rollers including two sets of independently operable control elements respectively connected to eachfcarrier on opposite sides of the roller axis.

6. In friction transmission mechanism having coaxial toroidal -races and interposed rollers, a frame, a roller carrier for each roller trailing from a universal pivotal connection to the frame, means for reversing the direction of rotation of the races and rollers, and means for controllingv the ratio position of the rollers including two sets of independently operable control elements respectively connected to each carrier on opposite sides of the roller axis.

7. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a frame, a roller carrier for each roller universally pivoted to the frame, arms projecting laterally from each carrier on opposite sides of the roller axis, means for reversing the direction of rotation of the races and rollers, andcontrolmeans including two sets of independently operable control elements respectively connected to the arms on the carriers.

8. In friction transmission mechanism having coaxial toroidal races and interposedrollers, a frame, a roller carrier for each roller universally pivoted to the frame, arms projecting laterally from each carrier on opposite sides of the roller axis, means for reversing the direction of rotation of the races and rollers, and control means including two sets of independently operable control elements including links universally pivoted respectively to the carriers at opposite sides of the roller axis.

9. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a frame, a roller carrier for each roller trailing from a universal pivotal connection to the frame, arms projecting laterally from each carrier at opposite lsides of the roller axis, means for reversing the direction of rotation of the races and rollers, and control means including two sets of independently operable control elements including links connected to the ends of the arms projecting from opposite sides of the carriers.

10. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a

' frame, a roller carrier for each roller universally 75 pivoted to the frame, means for reversing the direction of rotation of the races, control means including an external control shaft, two sets of control elements respectively connected to each carrier on opposite sides of the roller axis, and means for selectively coupling either of said sets of control elements to the external control shaft and freeing the other.

1l. In friction transmission mechanism having lo coaxial toroidal races and interposed rollers, a frame, a roller carrier for each roller universally pivoted to the frame, means for reversing the direction of rotation f of the races and rollers, and control means comprising two independently l5 rotatable control collars coaxial with the races, links respectively universally pivoted eccentrically to each collar and to each roller carrier on opposite sides of the roller axis, and means for selectively rocking either collar and simultaneously 29 freeing the other.

12. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a frame, a roller carrier for each roller universally pivoted to the frame, means for reversing the 5 direction of rotation of the races and rollers, and

control means comprising two independently rotatable control collars coaxial with the races, means respectively connecting said control collars to each-carrier on opposite sides of the roller axis,

' Si) a coupling adapted to interlock 4with one collar or the 'other alternatively, and means for rocking the coupling.

13. In friction transmission mechanism having coaxial `toroidal races and interposed rollers, a

35 frame, a roller carrier for each roller universally pivoted to the frame,'means for reversing the direction of rotation of the races and rollers, control means comprising two independently rotatable control collars coaxial with the races, links 4o respectively universally pivoted eccentrically to each collar and to each roller carrier on opposite sides oi' the roller axis, a coupling adapted to interlock with one collar or the other alternatively and means for rocking the coupling.

:i5 le. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a frame, a roller carrier for each roller trailing from a universal pivotal connection to the frame, arms projecting from opposite sides of the carrier,

5o means for reversing the direction of rotation of the races and rollers, and control means comprising two independently rotatable control collars coamal with the races, links respectively universally pivoted eccentrically to each collar and to the arms on each roller carrier, and means for selectively rocking either collar and freeing the other.

15. In friction transmission mechanism having coaxial toroidal races and interposed rollers, a

59 frame, a roller carrier for each roller universally pivoted to the frame', means for reversing the ldirection of rotation of the races and rollers and. control means comprising two independently rotatable control collars loosely mounted coaxial 55 with the races, a coupling adapted to interlock vwith one collar or the other,` alternatively, and

cooperating means on coupling and collars for centering each collar when the coupling interiocks with it, connections between the collars re- 79 spectively and the roller carriers on each side of the roller axis, and means for rocking the coupling. r

16. In friction transmission mechanism having coaxial toroidal races and'interpcsed rollers, a-

75 ic, a roller carrier for each roller universally plvoted to the frame, means for reversing the direction of rotation of the races .and rollers, control means comprising a pair of opposltely facing cup-shaped collars having conoidal interior surfaces and locking dogs, a coupling arranged to 5 enter the cavity .of either collar and center it by engaging its conoidal interior surface, and provided with dogs cooperating with the dogs on the collars, to selectively interlock with either collar,

a connection extending from each collar to each carrier at points respectively on opposite sides of the axis of the roller, and means for rocking the coupling.

17. In friction transmission mechanism having a race, an adjustable roller, in peripheral power l5 transmitting engagement with the race, and a roller supporting means, control means including two sets of independently operable control elements operatively connected to the roller supporting means and arranged respectively to adjust the roller to a new ratio position dependent upon the sense of `rotation of the race, an external control. device, and movable coupling means responsive to the direction of rotation of the race and roller for connecting one or the other of said sets of J control elements to the external-control device.

18. In friction transmission mechanism having a reversible race, a roller, a frame, a roller carrier pivoted to the frame, control means including two sets of independently operable control 3') elements respectively connected to the carrier to tion oi rotation of the race arranged to be seized 40 by the clutch in initial rotation thereof in either direction, and trip mechanism for releasing the clutch after a partial rotation of said actuator in either direction.

19. In friction transmission mechanism having a reversible race, a roller, a frame, a roller carrier universally pivoted to the frame, control means including two sets of independently operable control elements respectively connected to the carrier on opposite sides of the roller axis, an external control device, means for connecting one or the other of said sets of control elements to the externalcontrol device in accordance with the direction oi rotation oi the races and rollers, said means comprising a tubular hub-like member rotatable in one direction or the other in accordance with the direction of rotation of the race, a coiled expansion sprlnglclutch element within the hublike member, an actuator within the spring clutch element for connecting one or the other sets of C0 control elements to the external control member, means on the actuator engaged by the extremltles of said spring clutch element, and ground trips fixed to the frame for contracting the spring clutch and releasing it from the hub-like member after a partial rotation in either direction.

20. In friction transmission mechanism having a reversible race, a roller, a carrier therefor, lndependent means connected to said carrier for controlling the ratio positions of the roller ouring forward and reverse driving, and means for rendering one or the other of said control means operative in accordance with the direction otrotatlon of the race and roller, said means comprislng a tubular hub-like memr rotatable by the race, a control tube coaxial with the hub-like member associated with means for rendering one or the other of said control means operative acco-rding to the direction of rotation of the race, an expansible coil spring clutch element disposed between said control tube and said tubular hublike member, abutments on the control tube at the ends of the spring clutch element, shoulders on the spring-clutch element adjacent the ends, and stationary trips arranged to engage the shoulders after a partial rotation of the control tube in either direction.

21. In friction transmission mechanism having toroidal races, interposed rollers, and universally mounted roller carriers, means for reversing the direction of rotation of the races and rollers; control means including two sets of independently operable control elements, means connecting one control element to each carrier at one side of the roller axis and means for connecting the other element to each carrier at the other side of the roller axis; movable coupling means adapted to engage one or the other control element alternatively, means for moving said coupling means into engagement with one or the other of said control elements, said coupling moving means comprising a-rotating actuating member and cooperating camming 'elements on said coupling means and rotary actuating member.

22. A combination as deilned in claim 21 in which said coupling means comprises a ring-like device having internal cam grooves and said rotary actuating member has means to engage the internal helical grooves of 'the coupling means.

23. A combination as dened in claim 21 in which said coupling means comprises a ring-like device having internal helical cam grooves merging into circular grooves, and said rotary actuatingmember has bosses engaging said grooves.

24. In a reversible, variable speed, toroidal race and roller transmission mechanism, independently operable forward and reverse drive roller-adjusting devices for changing the ratio positions of the rollers, an external control device, a coupling device connected to the external control device, automatic means for engaging said coupling device with the forward drive roller-adjusting device during forward rotation of the transmission mechanism and with the reverse drive roller-adjusting device during reverse rotation of the transmission mechanism, said automatic means comprising a rotatable control member for moving the coupling device, and means for rotating said control member in response to changes in sense of rotation of the transmission mechanism.

25. In a reversible, variable speed, toroidal race 1 and roller transmission mechanism, comprising power input means and a power output shaft coaxial with the races; independently operable for- Iward and reverse drive roller-adjusting means JOHN O. ALMEN. WINFIELD D. GOVE. 

